Nadine Dorries has been reinstated as a Conservative MP after having the whip withdrawn for taking part without permission in the ITV reality show I'm a Celebrity … Get Me Out of Here!

The MP for Mid Bedfordshire was suspended from the party last November after flying to Australia to compete in the show while parliament was sitting. She has been sitting as an independent MP since.

The former nurse, who entered parliament in 2005, insisted at the time that she had approval to take a holiday by the then chief whip Andrew Mitchell, although Mitchell said he had not been told what she was planning to do with her time off.

She is said to have apologised at a meeting with current chief whip Sir George Young, who had restored the whip with immediate effect.

"Nadine has apologised to the chief whip for absenting herself from her parliamentary duties without permission and has given assurances to the whips' office that she will follow the same procedure as other Conservative members of parliament before going away when the house is sitting," a Conservative party spokesman said.

Her acceptance back into the Tory fold comes amid speculation over Tory defections to Ukip following the poll surge by Nigel Farage's party, and unrest over David Cameron's leadership.

Dorries has been an outspoken critic of the prime minister and has previously described him and chancellor George Osborne as "arrogant posh boys".

It is understood the Ukip issue was not mentioned at her meeting with Sir George, which was described as "convivial".

Dorries, 55, said of her reinstatement: "I am delighted. It is long overdue."

It is understood that the offer to return to the party was unconditional and Dorries immediately accepted. After her suspension, Cameron said the MP needed to regain the affection of her colleagues before she could return.

Dorries had defended her appearance on the show saying it was a way to bring politics to the attention of a younger generation. She was the first contestant to be voted out of the jungle by television viewers.